Computers Articles

Cheat Sheet / Updated 11-15-2022

Whether you’ve purchased a new Mac with macOS Ventura pre-installed or you’ve upgraded from a previous version of macOS, you’ll find that Ventura makes your computer easier to use and offers myriad improvements to make you more productive. This Cheat Sheet includes information on things you should never do to your Mac; a compendium of useful and timesaving keyboard shortcuts; recommendations for backing up data; and website recommendations for smart Ventura users.

Cheat Sheet / Updated 11-15-2022

Whether you’ve purchased a new Mac with macOS Monterey pre-installed or you’ve upgraded from a previous version of macOS, you’ll find that Monterey makes your Mac easier to use and offers myriad improvements to make you more productive. This Cheat Sheet includes information on things you should never do to your Mac; a compendium of useful and timesaving keyboard shortcuts; a discussion of when folders are too full and when (and when not) to create subfolders; recommendations for backing up data; and a short discussion of iDevices and Continuity.

Cheat Sheet / Updated 11-01-2022

Linux can fulfill almost any need you have for the operating system on a desktop computer, but you must be able to tell it what you want to do in a way that it understands. You need to know common commands and how to access the help pages.

Article / Updated 09-15-2022

Investing appears to be complicated and complex. But if you can take some relatively simple concepts to heart and adhere to them, you can greatly increase your success. Here are ten time-tested principles of investing success. Following these principles will pay you big dividends (and capital gains) for many years to come. Regularly save and invest 5 percent to 10 percent of your income Unless you enjoy a large inheritance, you should consistently save 5 percent to 10 percent of the money you’re earning. When should you start doing this? As soon as you begin earning money on a regular basis. Preferably, invest through a retirement savings account to reduce your taxes and ensure your future financial independence. You can reduce both your current federal and state income tax bills (on the contributions) as well as these ongoing bills (on the investment earnings). The exact portion of your income you should be saving is driven by your goals and by your current financial assets and liabilities. Take the time to crunch some numbers to determine how much you should be saving monthly. Understand and use your employee benefits The larger the employer, the more likely it is to offer avenues for you to invest conveniently through payroll deduction, and with possible tax benefits and discounts. Some companies enable you to buy company stock at a reduced price. Often, the most valuable benefit you have is a retirement savings plan, such as a 401(k) plan that enables you to make contributions and save on your current income taxation. Also, after the money is in the account, it can compound and grow over the years and decades without taxation. If you’re self-employed, be sure to establish and use a retirement plan. Also take time to learn about the best investment options available to you — and use them. Thoroughly research before you invest The allure of large expected returns too often is the enticement that gets novices hooked on a particular investment. That’s a whole lot more appealing than researching an investment. But research you must if you want to make an informed decision. Be sure you understand what you’re investing in. Don’t purchase any financial product that you don’t understand. Ask questions and compare what you’re being offered with the best sources I recommend. Beware of purchasing an investment on the basis of an advertisement or a salesperson’s solicitation. Shun investments with high commissions and expenses The cost of the investments you buy is an important variable you can control. All fees must be disclosed in a prospectus, which you should always review before making any investment. Companies that sell their investment products through aggressive sales techniques generally have the worst financial products and the highest fees and commissions. Invest the majority of your long-term money in ownership investments When you’re young, you have plenty of time to let your investments compound and grow. Likewise, you have time to recover from setbacks. So with your long-term money, focus on investments that have appreciation potential, such as stocks, real estate, and your own business. When you invest in bonds or bank accounts, you’re simply lending your money to others and will earn a return that probably won’t keep you ahead of inflation and taxes. Avoid making emotionally based financial decisions Successful investors keep their composure when the going gets tough. You need the ability and wisdom to look beyond the current environment, understanding that it will change in the months and years ahead. You don’t want to panic and sell your stock holdings after a major market correction, for example. In fact, you should consider such an event to be a buying opportunity for stocks. Be especially careful about making important financial decisions after a major life change, such as marriage, the birth of a child, a divorce, job loss, or a death in your family. Make investing decisions based on your plans and needs Your investment decisions should come out of your planning and your overall needs, goals, and desires. This requires looking at your overall financial situation first and then coming up with a comprehensive plan. Don’t be swayed and influenced by the predictive advice offered by various investment pundits or the latest news headlines and concerns. Trust that you know yourself and your financial situation better than anyone else does. Tap information sources with high-quality standards You need to pare down the sources you use to keep up with investing news and the financial markets. Give priority to those that aren’t afraid to take a stand and recommend what’s in your best interests. The public clearly has an appetite for opinion shows; on the political left, you have programs on CNN and MSNBC. On the political right, FOX has some popular conservative opinion shows. Political partisans distort the news rather than report the news, and they prevent you from better understanding what’s really going on so you can make informed decisions. Political partisans overstate the impact that the president and others can have over our economy and financial markets. Stay away from outlets that cater to advertisers or are driven by an ideological agenda. Trust yourself first Look in the mirror. You’ll see the best financial person you can hire and trust. What may be missing is enough education and confidence to make more and better decisions on your own, which this book can assist you with doing. If you need help making a major decision, hire conflict-free advisors who charge a fee for their time. Work in partnership with advisors. Never turn over or abdicate control. Invest in yourself and others Don’t get so wrapped up in making, saving, and investing money that you lose sight of what matters most to you. Invest in your education, your health, and your relationships with family members and friends. Having a lot of money isn’t worth much if you don’t have your health and people with whom to share your life. Give your time and money to causes that better our society and our world.

Article / Updated 08-16-2022

The only time you need to restore a system image on your Windows PC is when the entire hard drive is dead, missing, or replaced with a cheese sandwich. With all that data gone, you have to rely upon three items: A recovery volume: Use this media to start the PC and access the Windows Recovery Environment. The tools presented help you navigate through recovery. The system image: Use this information to restore Windows and other partitions as a base to rebuild your computer system. Tools on the recovery volume help you use the system image information. File History: Finally, with Windows restored, you run the File History program to recover your PC's lost files and programs. You don't need to restore a system image if you merely need to recover from a Windows disaster. The first thing you should try is System Restore. Second, you can try to reset the PC. Otherwise, the process of using the system image works like this: Start the PC by using the Windows Recovery Environment. Choose Troubleshoot. Choose Advanced Options. Choose System Image Recovery. Point the system image recovery tool at the location of the system image files, and then sit back and wait as the system is rebuilt. Yes, the process is more complex than four simple steps. For example, you may need a replacement hard drive. The good news is that you have the system image if you need it. Along with a recent backup, you can fully restore your system no matter what happens to the computer.

Article / Updated 08-16-2022

Once you have the basics, you can now complete your first sketch. In front of you now should be an Arduino Uno R3, a USB cable, and a computer running your choice of operating system (Windows, Mac OS, or Linux). Find the Blink Sketch To make sure that the Arduino software is talking to the hardware, you upload a sketch. What is a sketch, you ask? Arduino was created as a device that allows people to quickly prototype and test ideas using little bits of code that demonstrate the idea — kind of like how you might sketch out an idea on paper. For this reason, programs written for Arduino are referred to as sketches. Although a device for quick prototyping was its starting point, Arduino devices are being used for increasingly complex operations. So don't infer from the name sketch that an Arduino program is trivial in any way. The specific sketch you want to use here is called Blink. It's about the most basic sketch you can write, a sort of “Hello, world!” for Arduino. Click in the Arduino window. From the menu bar, choose File→Examples→01.Basics→Blink. A new window opens in front of your blank sketch. Identify your board Before you can upload the sketch, you need to check a few things. First you should confirm which board you have. You can choose from a variety of Arduino devices and several variations on the USB board. The latest generation of USB boards is the Uno R3. If you bought your device new, you can be fairly certain that this is the type of board you have. To make doubly sure, check the back of the board. You should see details about the board's model. Also worth checking is the ATMEL chip on the Arduino. The ATMEL chip is the brains of the Arduino and is similar to the processor in your computer. Because the Uno and earlier boards allow you to replace the chip, there is always a chance, especially with a used board, that the chip has been replaced with a different one. Although the ATMEL chip looks quite distinctive on an individual board, if you compare it to an older Arduino, telling them apart at first glance would be difficult. The important distinguishing feature is written on the surface of the chip. In this case, you are looking for ATmega328P-PU. Configure the software After you confirm the type of board you are using, you have to provide that information to the software. From the Arduino main menu bar (at the top of the Arduino window on Windows and at the top of the screen on Mac OS X), choose Tools→Board. You should see a list of the different kinds of boards supported by the Arduino software. Select your board from the list. Next, you need to select the serial port. The serial port is the connection that enables your computer and the Arduino device to communicate. Serial describes the way that data is sent, one bit of data (0 or 1) at a time. The port the physical interface, in this case a USB socket. To determine the serial port, choose Tools→Serial Port. A list displays of devices connected to your computer. This list contains any device that can talk in serial, but for the moment, you're only interested in finding the Arduino. If you've just installed Arduino and plugged it in, it should be at the top of the list. For OS X users, this is shown as /dev/tty.usbmodemXXXXXX (where XXXXXX is a randomly signed number). On Windows, the same is true, but the serial ports are named COM1, COM2, COM3, and so on. The highest number is usually the most recent device. After you find your serial port, select it. It should appear in the bottom right of the Arduino GUI, along with the board you selected. Upload the sketch Now that you have told the Arduino software what kind of board you are communicating with and which serial port connection it is using, you can upload the Blink sketch. First click the Verify button. Verify checks the code to make sure it makes sense. This doesn't necessarily mean your code will do what you are anticipating, but it verifies that the syntax is written in a way Arduino can understand. You should see a progress bar and the text Compiling Sketch for a few seconds, followed by the text Done compiling after the process has finished. If the sketch compiled successfully, you can click the Upload button next to the verify button. A progress bar appears, and you see lots of activity on your board from the two LEDs marked RX and TX. These show that the Arduino is sending and receiving data. After a few seconds, the RX and TX LEDs stop blinking, and a Done Uploading message appears at the bottom of the window. You should see the LED marked L blinking away reassuringly: on for a second, off for a second. If that is the case, give yourself a pat on the back. You've just uploaded your first piece of Arduino code and entered the world of physical computing! If you don't see the blinking L, review the preceding steps. Make sure you have installed Arduino properly and then give it one more go. If you still don't see the blinking L, check out the excellent troubleshooting page on the official Arduino site. Without breaking a sweat you've just uploaded your first sketch to an Arduino.

Step by Step / Updated 08-02-2022

When you use a firewall — and you should — you change the way your computer communicates with other computers on the Internet. The firewall blocks all incoming communications unless you open a port in the Windows firewall to let a specific IP communicate with your computer. For example, if you want to play many online games. Most first-time firewallers are overwhelmed by the idea of opening a port. Although open ports are a security threat, sometimes you truly need to open one. Still, you may need to open a port to enable a specific application. For example, when you select the check box to allow Remote Desktop, you’re opening port 3389. That’s the security price you pay for enabling programs to talk to each other.In general, if you need to open a specific port, the documentation for the program (game, torrent downloader, file sharer) will tell you . . . assuming you read the program’s manual.

Step by Step / Updated 08-02-2022

Setting up a firewall is an effective way to protect your computer from outside cyber attackers and malicious software. But keep in mind that by setting up a firewall, you are changing the way your computer communicates with other computers on the Internet. The firewall blocks all incoming communications unless you set up a specific inbound exception in the Windows firewall to let a program in. Some of your programs won’t respond until they receive a signal via the Internet. If you have a program that doesn’t poke its own hole through the Windows Firewall, you can tell the firewall to allow packets destined for that specific program — and only that program — in through the firewall.

Article / Updated 07-20-2022

Basic Arduino sketches can get you quite a long way, but when you become more advanced you need to know about libraries. Libraries provide extra functionality to your Arduino sketch, either to use specific hardware or to incorporate more complex functions in software. In the same way that you’d go to a physical library to learn something new, you include libraries in your code to teach your Arduino something new. By including a library in a sketch, you can quickly and easily access functions to help you achieve your goals. Getting started with complex hardware or software can be difficult. Luckily, a lot of people have taken the time to document their progress and have released libraries, often with examples, that you can easily integrate into your own Arduino sketches. From this, it’s possible to get something working and gain a better understanding of it. This learn-by-doing approach of Arduino allows you to make a lot of progress quickly and easily with hardware or software that would otherwise be a huge challenge. Standard Arduino libraries Standard Arduino libraries refers to a selection of the libraries included in the current release of Arduino at the time of writing (1.8.5). The standard libraries cover a wide range of subject areas and are usually popular topics that have been heavily documented. You can find these libraries by choosing Sketch →   Include Library →   Manage Libraries. Choosing a library includes one line at the top of your current sketch, such as #include <EEPROM.h>. Before you attempt to understand a library, you should try an example of it. You'll find examples at the bottom of the menu that appears at when you choose File →   Examples. Here is a brief description of what each Arduino library does: EEPROM: Your Arduino has electronically erasable programmable read-only memory (EEPROM), which is permanent storage similar to the hard drive in a computer. Data stored in this location stays there even if your Arduino is powered down. Using the EEPROM library, you can read from and write to this memory. Ethernet: After you have your Ethernet shield, the Ethernet library allows you to quickly and easily start talking to the Internet. When you use this library, your Arduino can act either as a server that is accessible to other devices or as a client that requests data. Firmata: Firmata is one way to control your Arduino from software on a computer. It is a standard communication protocol, so you can use the library to allow easy communication between hardware and software rather than write your own communication software. LiquidCrystal: The LiquidCrystal library helps your Arduino talk to most liquid crystal displays (LCDs). The library is based on the Hitachi HD44780 driver, and you can usually identify these displays by their 16-pin interface. SD: The SD library allows you to read from and write to SD and microSD cards connected to your Arduino. SD cards need to use SPI to transfer data quickly, which happens on pins 11, 12, and 13. You also need to have another pin to select the SD card when it’s needed. Servo: The Servo library allows you to control up to 12 servo motors on the Uno R3 (and up to 48 on the Mega). Most hobby servos turn 180 degrees, and using this library, you can specify the degree that you want your servo(s) to turn to. SPI: The Serial Peripheral Interface (SPI) is a method of communication that allows your Arduino to communicate very quickly with one or more devices over a short distance. Example of this communication include receiving data from sensors, talking to peripherals such as an SD card reader, and communicating with another microcontroller. SoftwareSerial: The SoftwareSerial library allows you to use any digital pins to send and receive serial messages instead of, or in addition to, the usual hardware pins (0 and 1). This capability is great if you want to keep the hardware pins free for communication to a computer, allowing you to have a permanent debug connection to your project while still being able to upload new sketches or to send duplicate data to multiple serial devices. Stepper: The Stepper library allows you to control stepper motors from your Arduino. This code also requires the appropriate hardware to work, so make sure to read Tom Igoe’s notes on the subject. Wi-Fi: The WiFi library is based on the Ethernet library listed previously, but with alterations specific to the Wi-Fi shield to allow you to wirelessly connect to the Internet. The WiFi library also works well with the SD library, allowing you to store data on the shield. Wire: The Wire library allows your Arduino to communicate with I2C devices (also known as TWI, or two-wire interface). Such devices could be addressable LEDs or a Wii Nunchuk, for example. Additional Arduino libraries Many libraries aren’t included in the Arduino software by default. Some libraries are for unique applications such as specific hardware or functions; others are refinements or adaptations of existing libraries. Luckily, Arduino makes including these easy, so you can quickly try them all to see which are right for your needs. Most libraries are easily installed by choosing Sketch →   Include Library →   Manage Libraries from the Arduino IDE menu. The Library Manager dialog box displays an easily searchable list of libraries submitted to the Arduino servers and approved for release. Libraries may also be distributed as ZIP files that have the same name as the library; for example, the capacitive sensing library CapSense should be distributed as CapSense.zip and should contain a folder of the same name when unzipped. Inside the folder there are files ending in .h and .cpp, such as CapPin.h and CapPin.cpp, and maybe even an Examples folder. If your .zip file contains only loose .h and .cpp files, you should place them in a folder with a library name. Sometimes you may find many .h and .cpp files that all perform different functions in the library, so make sure they're all inside the folder. In the latest release of Arduino (1.8.5 at the time of this writing), it’s easy to include libraries distributed as ZIP files. Simply choose Sketch →   Include Library →   Add .ZIP Library and select the ZIP file containing the library. After the library is installed, restart Arduino and choose Sketch →   Include Library to check that your library is in the list. If the library has an Examples folder, you should also be able to see the examples by choosing File →   Examples and then choosing the name of the library. That’s all there is to installing a library. Removing a library is as simple: just take the library folder out of the Arduino Sketch folder. Contributed Arduino libraries A long list of community-contributed libraries appears on the Arduino libraries page and an exhaustive list appears on the Arduino Playground. To become familiar with contributed libraries, start with CapSense and TimerOne, two commonly used and helpful libraries: CapSense: The CapSense library allows you to make one or many pins on your Arduino into capacitive sensors. This feature allows you to make simple touch, pressure, or presence detection sensors quickly and easily with little hardware. The Arduino Playground page has a lot of useful information, but a more recent version of the code can be found on GitHub. TimerOne: TimerOne (also called Timer1) uses a hardware timer on your Arduino to perform timed events at regular intervals. It’s a great library for reading sensor data regularly without interrupting what’s going on in the main loop. You can find a TimerOne page on the Arduino Playground and an up-to-date version of the library on Google Code. If you’re keen to understand libraries more and maybe even write your own, check out the introduction to writing your own libraries on the Arduino GitHub page.

Article / Updated 07-19-2022

You can us the standard USB Arduino board, but you should be aware that many others exist, all designed with different needs in mind. Some Arduino boards offer more functionality, and others are designed to be more minimal, but generally they follow a design similar to that of the Arduino Uno. The Arduino Uno is a great board, but here are some other options if you feel like venturing out. Official Arduino boards Although Arduino is open source, it is also a trademarked brand, so to guarantee the quality and consistency of its products, the Arduino team must properly approve new boards before they are officially recognized and can bear the name Arduino. You can recognize official boards first by the name — Arduino Pro, Arduino Fio, or Arduino LilyPad, for example. Other nonofficial boards often include Arduino compatible or for Arduino in the name. The other way to recognize an official Arduino, made by the Arduino team, is by the branding (in the most recent versions): They are turquoise and display the infinity symbol somewhere on the board, along with a link to Arduino’s site. Some other companies also have their boards accepted as official boards, so you may find other company names printed on them, such as Adafruit Industries and SparkFun. Because the schematics for the Arduino board are open source, unofficial Arduino boards have a lot of variation, which people have made for their own needs. These boards are usually based on the same microcontroller chips to remain compatible with the Arduino software, but they require extra consideration and reading to be sure that they will work as expected. The Seeeduino v4.2 (by Seeed Studio), for example, is based on the Arduino Uno and is 100 percent compatible but adds various extra connections, switches, and sockets, which may be of more use to you than an official Arduino board in certain situations. Official boards are the safe option for beginners to choose because the majority of Arduino examples online are based on these boards. Because of this, official boards are more widely used, and because of that, any errors or bugs in the board design are likely to be remedied with the next revision or at least well documented. Arduino Leonardo The Leonardo has the same footprint (shape of circuit board), but the microcontroller used is different and can be recognized as a keyboard or mouse by a computer. In the “Hacking Other Hardware” bonus chapter of Arduino For Dummies, 2nd Edition, you can find more detail about the differences between this board and the Uno and how to use it. Arduino Mega 2560 R3 As the name suggests, the Arduino Mega 2560 R3 is a bigger board than the Arduino Uno R3. It is for people who want more: more inputs, more outputs, and more processing power! The Mega has 54 digital pins and 16 analog pins whereas the Uno has a measly 15 digital and 6 analog pins. Arduino Mega ADK The Arduino Mega ADK is essentially the same board as the Mega 2560 Arduino but is designed to interface with Android phones. This means you can share data between your Android mobile or tablet and an Arduino to broaden the range of either. Arduino Nano 3.0 The Arduino Nano 3.0 is a condensed Arduino that measures just 0.70″ x 1.70″. This size is perfect for making your project smaller. The Nano has all the power of an Arduino Uno (both use the same ATmega328 microcontroller), but it's a fraction of the size. The Nano also handily fits into a breadboard, making it ideal for prototyping as well. Arduino Mini R5 Despite what the names suggest, the Arduino Mini R5 is smaller than the Nano. This board also uses the same ATmega328 microcontroller chip but is condensed further, removing all header pins and the Mini-USB connector of the Nano. The Mini board is great if space is at a premium, but it does require great care when connecting because an incorrect connection can easily destroy the board. Arduino 101 The Arduino 101 uses the Intel Curie module to provide a board that’s as easy to use as Arduino but with the latest Bluetooth low energy technology. It also features a six-axis accelerometer to detect movement, making it a great companion for any wearable technology projects or for talking to other Bluetooth devices. Arduino MKR1000 The Arduino MKR1000 is a simple but powerful board, combining a 32-bit processor with a Wi-Fi module. It’s perfect for linking sensors and actuators to the Internet or prototyping your next Internet of Things (IoT) project. Along with its small form factor, it has a handy battery connector to allow you to take your project on the move. Contributed (approved) Arduinos Many Arduino boards are now standardized and designed by the Arduino team. However, some have been contributed by other companies, such as Adafruit Industries and SparkFun, and are recognized as official boards. LilyPad Arduino USB The LilyPad Arduino USB was made for projects in which technology is combined with textiles to aid in the development of e-textiles or wearable electronics projects. The LilyPad and its accompanying breakout boards (printed circuit board that make it easy to integrate various components without the need to build your own boards) can be sewn together using conductive thread instead of conventional wire. This board was designed and developed by Leah Buechley of MIT and SparkFun Electronics. If you’re interested in e-textiles or wearable electronics, check out the excellent tutorial on SparkFun’s site that introduces the latest version of the board and the ProtoSnap kit. Arduino Pro The Arduino Pro is a minimal and super skinny Arduino, by SparkFun Electronics, based on the same microcontroller as those used in the Uno. It comes without any of the normal headers or sockets but has all the same capabilities of an Uno. It’s ideal when height is at a short supply. In addition, it has a battery socket, which allows you to easily make your project portable. Arduino Pro Mini The Pro Mini is another SparkFun product; this one pushes the minimalism of the Arduino Pro to new limits. In the scale of Arduinos, the Pro Mini sits neatly between the Nano and the Mini. It has none of the header pins or the Mini-USB port of the Nano, and is slightly more spread out than the Arduino Mini. The Pro Mini has none of the safety features of the Uno, so take great care when wiring because a wrong connection can easily destroy the board.